A visit to Gravity Falls
by 3710rice
Summary: Undercover jobs aren't always easy. In fact, they can be quite hard if there are a pair of twins that know you definitely aren't normal. Set just before sock opera and just after warp tour.
1. Shapechanger

**AN: Behold! My dumb crossover idea! It's pretty simple and this'll maybe have 3 or 4 chapters, and no crazy overarching story, because I am not good at those. More of a slice of life if you can have crossover slices of life. Yup.**

**If you like it, a review, favorite, or follow would be much appreciated.**

* * *

"Steven," Garnet said in her casual, flat voice. "you are going on your very own mission."

Steven immediately broke into a huge smile, his eyes glimmering. "I am!?"

"Yes. We are looking into possible gem activity in a small city called Gravity Falls, Oregan. We need someone to blend in and get information from the locals while we study the gem structures in that area. See if they've seen anything weird."

"But why not you, or Pearl, or Amethyst?" Steven questioned , and then quickly added, "not that I'm complaining."

"Um, Steven, have you even looked at us?" Amethyst blurted out. "We aren't exactly the 'blending in' type."

"Oh. So you want someone human-y then?"

"Basically." Garnet walked over to the warp pad, Pearl and Amethyst following suit.

"Now Steven, you can't tell anyone about your gem. For this mission you are Steven Universe , ordinary human boy." Pearl gestured him up onto the warp pad. "We got you a place to stay and everything."

"Wait! This is going to be a more than one day mission?" Steven broke into a huge smile. The gems hardly ever went on multi-day missions, and they never brought him with them. His expression turned to concern as a thought crossed his mind. "But what about Lion? I can't leave him here all alone!"

Pearl sighed. "Bring him if you must, but you can't let anyone see him."

"Okay!" Steven woke up the gigantic sleeping cat and dragged him onto the warp pad, the five of them warping off to the odd little town of Gravity Falls.

* * *

Dipper cleaned the glass on the mini-dragon exhibit (which was actually a lizard with tiny fake wings glued on) and stared at his reflection. It was mid-morning and there was absolutely nothing interesting happening. Usually by now at the very least there was _something,_ even if it was as small as Stan announcing a new gift shop item. But right now there wasn't even a customer.

"I'm sooo booored." Mabel whined. "Something needs to just happen already!"

Stan walked into the room. "Kids, we're having a guest. If he's creepy, don't follow him to his room. That is all." Stan walked back out, satisfied in his ability to announce important plot points at exactly the right times.

"New guest!" Mabel stood up immediately. "I wonder when he'll be getting here? I love new guests!"

"I don't know, but I hope he'll be interesting. Not a werewolf would be nice."

Mabel nodded at Dipper's comment, remembering the last guest that spent the night at the mystery shack. She had learned that werewolves are not quite as hot in real life as they are described in books. And movies. And well, anything, really. They are quite scary, in fact.

The gift shop bell rang and the twins rushed to the store portion of the shack. Waiting for them was a brown haired boy, maybe 11 years old, carrying a suitcase. He wore a pink shirt with a star in the center and flip flops with jeans. "Hi! I was told this was the mystery shack, I think I'm staying here for a few days!"

"Oh my god! Stan didn't tell us it was a kid that was staying!" Mabel immediately ran over to the boy. "I'm Mabel! My brother over there is Dipper."

"I'm Steven, a completely normal human that is by no means anything else."

Dipper squinted at Steven. Either this kid was hiding something and really bad at it or he was really bad at making jokes. He looked normal enough. Just like any other kid. Hm.

"Welcome to the shack, Steven. I'll show you where you will be spending the night." Dipper gestured over Steven and began to lead him to the room where they had found the body swapping carpet. "Futon, bathroom. Any questions?"

"Um, yeah." Steven scratched the back of his head. "Have you seen anything odd around here?"

Dipper stared for a second. Okay, this boy was hiding something. "Maybe. Why do you ask?"

"Just curious."

"Alright. Well then, I'll be in the attic if you need anything." Dipper walked up the stairs. Steven *looked* normal enough. But why would he include the "perfectly normal human" bit and ask about weird stuff? He looked out the window and did a double take. Slinking out of the entrance to the shack there was a lion, but not any lion. This lion was pink.

He sprinted back downstairs and ran to his sister, who was sitting at the table.

"Mabel! Did you just see anything?"

She shook her head. "Why?"

"There was a lion! Coming out of the shack! But it wasn't like a normal lion, it was pink!"

"Awww, a pink lion! That sounds adorable!" She looked at Dipper. "Calm down bro. Let's ask Steven, maybe he saw it?"

Dipper nodded. If Steven acted strange about this then maybe he would know that he was onto something.

The twins walked over to Stevens room. The door was wide open, and they could see it.

But Steven was nowhere to be seen.

* * *

Dipper flicked through the journal, looking for anything on lions. Nothing. But then a page caught his eye.

_Shapechangers_

_Shapechangers are generally humanoid creatures that can turn into something else. They differ from shapeshifters in that they generally are limited to one or two forms and they maintain physical differences from whatever they shapeshift into (eg color or size). They also have a main form that, on all outward appearances, looks human. They often maintain a cheerful demeanor to throw off any suspicion._

Dipper gasped. It all made sense! Steven was a shapechanger, that was a very possible explanation. He could turn into a lion.

He turned on the blacklight. _Very dangerous and aggressive- avoid at all costs. If you come into contact with one, do not engage._ He shined the light over the weaknesses section of the page. _Beeswax can be effective in expelling young ones._

"Hmm." Dipper mumbled, just to himself. "Beeswax. I think Mabel has some beeswax chapstick."

* * *

The trap was set. The doorway to Steven't room had been completely lined with beeswax. Three whole tubes, in fact. The journal said the physical act of walking through the doorway should weaken them to the point that they are dispelled. According to the journal, even older ones will be noticeably affected. So either way Dipper could confirm he was a shapechanger.

Dipper heard footsteps coming down the hall and hid inside the room. Holding his breath, the waited as Steven appeared just outside the doorway.

_Step. _Steven paused to look over his shoulder, as if checking that no-one was following him.

_Step_. Almost there.

And Steven was in the room. Unaffected, looking just as he did before.

Dipper let out his breath. Okay, so he wasn't a shapechanger. Good news, right? That would surely mean that Steven was just a normal human being, right?

Probably.


	2. Spherical

Dipper slowly crawled out from his hiding place as Steven was in the bathroom. He snuck out the door and back to the gift shop, where Mabel was manning the cash register.

"Mabel." Dipper whispered. "We need to talk." She nodded and the two ran off into the house portion of the shack.

"What's wrong Dip?"

Dipper swallowed. "I think something's up with Steven."

Mabel rolled her eyes. "Dipper, you say that about everyone. Sometimes it isn't true. He seems pretty normal to me."

"I know, but what about the lion?! That cannot be a coincidence. That kid is definitely hiding something. I mean, 'completely normal human being and by no means else'? Who says that?" Dipper said. "And he asked me if I'd seen anything weird."

"Maybe he's just interested in the unexplained. Come on, let's go ask him." Mabel skipped down the hall. She knew her brother was right a good portion of the time, but usually there was something off about the person first. Steven seemed pretty normal.

"Mabel..." Dipper grumbled and ran after her.

Steven was sitting in his room casually hanging off the futon, thinking up excuses to keep his cover, when Mabel walked in. "Hey! Mabel, was it?"

"Yeah!" Mabel leaned on the doorframe and then immediately stopped. "Ew, what _is_ this?' She examined the goop now on her sweater. Steven shrugged.

Dipper broke in. "Beeswax. Sorry."

Steven looked at Dipper. "Why is there beeswax on the doorframe?"

Dipper gulped and looked away. Mabel spoke up. "So, my brother thinks you're like some freaky monster or something. Is that true?"

Steven looked at the twins. He obviously was not a good enough lier. They already knew he wasn't just here on vacation. "Nope." He said in a faint voice. He regained his voice after a second. "No, I am completely and totally normal, I swear." It came out a bit too fast, and the twins did not look convinced.

"Alllriiight." Dipper said incredulously.

An awkward silence fell into place for a few seconds before Mabel broke it. "Hey, come have pancakes with us. We were just about to get some."

"Oh yeah, come get pancakes with us!" Dipper played along, hoping he could figure out more about Steven over brunch.

Steven's eyes lit up. "I love pancakes! They're like my favorite breakfast food and my third favorite food ever!" Steven flipped himself upright and slipped on his sandals.

The three walked out of the shack and toward Greasy's diner.

* * *

"So, Steven, where are you from?" Dipper inquired over a large stack of pancakes, which Steven had graciously paid for.

"This place down in Delaware, it's really small, you probably haven't heard of it." Steven said, taking a bite of his pancake.

"And why did you come to Gravity Falls? Where are your parents?"

"My parents are in Portland but they know I like mystery stuff so they brought me here." Steven lied, his explanation prepared only half an hour earlier, on the futon.

Oh. That explained why he cared about Dipper having seen strange things. "Tell you what, when we're done eating I'll show you this really cool place I found." Dipper would normally not tell anyone about the mysteries of Gravity Falls (except Mabel, Soos and Wendy, of course) but this place was really calm and it was big enough and close enough he could've found it on accident. It also definitely fell under the category of 'mystery stuff'.

The three ate their pancakes, Dipper hanging back while Mabel and Steven talked and made jokes and chatted with each other.

* * *

Dipper guided Steven into the forest. Mabel had gone home, as he had shown her this place shortly after he'd found it. They walked for several minutes until they reached their destination.

The pair walked into a huge clearing, where in the center, made perfectly from some sort of crystal, was a circular platform about 30 feet in diameter. In the middle of that platform was a pillar with a blue crystal sphere floating above it.

Steven instantly knew this was what the Gems were looking for. He had seen enough gem architecture to recognize it when he saw it. He casually walked up. "Woah."

Dipper looked proud of his find. "Pretty cool, right?" He stepped up onto the platform. "Come on, it's sturdy."

Steven cautiously stepped up. It would be pretty awkward if it did something because of his gem. He let out his breath when nothing happened. "It's awesome!"

The two walked up to the center. "I'm not sure what this is." He poked the ball, displacing it for a second before it popped back into place. "Here, touch it. I think it's magnetic, but it's balanced really well." He grabbed the ball with both hands and attempted to pull it out but was unable to.

Steven shook his head. "No thanks."

Dipper looked at him puzzledly. "Why not? It won't hurt you or anything."

Steven felt a pit open up in his stomach. He knew, never mind how, that if he touched it something would happen. But, against his instincts, he touched it.

The sphere tumbled out of midair and onto the floor. Dipper stared at Steven, wide eyed. "How did you do that!?"

"Uh. Must've hit it in the right-" Steven was shushed by Dipper as he noticed the sphere glowing and morphing.

"Never mind that. What is it doing?" Dipper leaned it closely but Steven pulled him back. A loose form took shape. One of a huge creature with wings.

"Dipper! Come on! We have to go!" Steven jerked back Dipper before it began to expand. But it was too late. The light faded, and in a solid form was a dragon-like creature the size of a bus. On its neck was the gem they were staring at only moments before.

"Dipper, now!" Steven began to panic and dragged his new friend away. Dipper regained his senses and the two began to run away.

They were almost to the edge of the clearing when Steven heard a loud "FWOOSH" and out of the corner of his eye saw a stream of lightening shooting directly at them.

His and his new friend's lives hung in the balance. Now was not the time for cover. The gems would have to forgive him. He focused and, in the nick of time, a protective bubble formed around Steven and Dipper.

"Wha?" Dipper looked at the rose-tinted substance that had just encased them. "Did you-"

"There isn't time!" Steven cried. The bubble popped and Dipper was shocked to see the pink lion run out of the bushes right toward the young boys. Dipper watched, his brain running a million miles per hour, as Steven ran right toward the lion. So they were together! Not that it was that surprising, really,bafter having seen the bubble. It was the same color, and while that might not mean much, he saw the lion immediately after Steven's arrival. More surprising was Steven running face first into the lion's mane, disappearing into it for a couple seconds and then jumping out with a sword. A freaking _sword!_

This was incredible.

Steven charged toward the dragon, unsheathing the sword. He ran towards the dragon, doing his best to avoiding the lightening being shot at him. After a few very close calls, he was at the dragon's feet. Steven shut his eyes tight and made a blind slash at the dragon, his hands shaking.

_Shnk_

The sword slashed deep into the dragon's belly and it began to glow for a few seconds before fading, dropping the spherical gem from before. Steven dove and grabbed the ball before it could hit the ground.

Dipper blinked. Okay. The eleven year old just took down a dragon. Well. His brain wasn't seeming to work right. He blinked off the confusion and stared at Steven.

"How did you do that?"

Steven jumped up, looked over his shoulder with wide eyes and ran into the woods.


	3. End

**Last chapter! I hope you liked this story. Sorry about the rushed plot and how long it took me to update. Anyway I'd still love advice on how to improve my writing, so if you have any don't be afraid to tell me!**

Dipper immediately broke into a sprint after Steven. Steven had dropped the sword when he ran into the woods, and he passed the lion grabbing it in his mouth. But no matter that, he had to catch Steven. He had a lot of practice running through these woods (with all the monsters and stuff), and as far as he knew Steven did not. So probably all the younger boy had on him was about a 20 second head start. Sure enough, he could hear Steven crashing though the woods ahead of him. Dipper sped up, leaping over logs until he could see the back of Steven's shirt.

Gathering up every bit of strength he had, Dipper leaped on Steven, tackling him to the ground.

"Aack!" Steven gasped, struggling to break free.

Dipper did his best to hold the squirming tween still. Steven was certainly stronger than he looked. "I'm not letting go till you tell me what just happened!"

"Well, I won't tell you what happened until you let go!" Steven responded before wildly flailing in an effort to get Dipper to release his hold.

It worked. His elbow slammed right into Dipper's gut, launching him off and back several feet until he crashed into a tree headfirst.

"Ow"!" Dipper sat up, dazed. He looked as Steven stood up and appeared as if he was going to run off again but then looked back at Dipper. He was surprised as the tween stepped back over to him. Dipper felt a sharp pain above his eye and he raised his hand to it only to feel warm liquid on his fingers.

"Careful," Steven said, "you cut your head, and it looks pretty bad." His voice was laced with worry. "Okay. Ummm. I don't know much first aid. But, uh, I can take you back to the Shack. Or there's..." He shook his head, cutting himself off.

Steven extended a hand to Dipper, who took it. "I'm fine. But you still need to explain."

"Later. But now we need to patch you up." The half-gem pulled Dipper up. This was quite a predicament he was in. He needed to somehow tell the boy the truth without actually saying it. An idea popped into his head. Yes or no questions- Dipper would ask them and he could answer with yes or no. That made sense- plus he wouldn't be saying the details, so he technically wouldn't be breaking his promise to the Gems.

"How do I know you won't run off once we reach Stan's?" Dipper questioned. "Heck, how do I know you'll bring me back as opposed to just dumping me in the forest?"

"Wow, you need to be more optimistic." Steven said. "But you can trust me. I didn't mean to hurt you and I'm really, really sorry. I want to make sure you're okay."

Reluctantly, Dipper walked with Steven out of the forest.

"Okay I can't really tell you why what happened did happen. But you can ask yes or no questions and I'll answer them as truthfully as I can." Steven trodded along beside Dipper.

"Why can't you tell me?"

"Anyway, what's your first question?" He ignored Dipper's inquiry.

The twin sighed. "Fine. Do you fight monsters a lot?"

"Yes." Steven answered.

"I think I already know the answer to this, but is the lion your pet?"

Steven paused. "Yes, but he does what he wants."

"Okay. You did summon the bubble, right?"

"Yup."

"So are you a wizard or something like that?" It was a long shot- wizards weren't real as far as he knew. But it was something.

"No."

"Didn't think so... Hm... Is magic involved at all?"

"Yes."

"Are you even a human, then?"

Steven thought for a moment. "Kind of?"

"What does that mean?!" Dipper exclaimed

"Ummmmmmm." Steven shut his mouth. He wanted to explain but he knew he couldn't. He continued walking.

"What does it mean?" Dipper pressed.

"Mmmmm..." Steven gave in. "It means that I'm half space rock I guess but I'm not gonna say any more!"

"Half space rock?" Dipper stopped walking, ignoring his stinging eye.

"Yeah. But I won't explain any more." Steven turned back toward Dipper. "Come on! I want to fix up that cut."

Dipper planted his feet. "Maybe I won't go until you explain." He knew that Steven seemed to care an almost unnatural amount that he wasn't hurt. He could use this to his , it was kind of mean, but half space rock? You can't just say that and not explain. Really.

"Nooo come on, please."

"Nope."

Steven looked conflicted for a moment. He looked around, thinking about what to do. He could, theoretically, just heal Dipper with his spit and run, but he knew that Dipper was a lot faster that he was. Unless he could get lion. But lion hardly even responded to his name unless there was some sort of threat to Steven's life, and Dipper wouldn't really kill him. Even then, he wasn't 100% sure his healing would even work. It didn't work last time.

"Maybe I'll just leave you here." Steven said as he crossed his arms.

"Fine."

"Fine." Steven turned and began to walk away but found it difficult to leave Dipper alone. What if there were other gem monsters roaming these woods? What if it hurt Dipper even more? Steven stopped walking and turned back. Why did he have to be so nice?

"Ughhh fine. But you can't tell anyone I told you. My mom was an alien that was called a gem, which I guess means they get their power and form and stuff from a gemstone somewhere on their bodies. She gave up her form to be able to have me with my dad, who's a human. There. Can we go back to the shack now?"

Dipper stared at Steven. Then he remembered something. "Wait, what happened to the sphere that had turned into the dragon?" It wasn't in Steven's hand, and it sure wasn't small enough to fit in his pocket.

Steven looked at Dipper, a pained expression on his face. "Please can't we just fix you up? Pleeeeeeaaaase?" He gently grabbed Dipper's hand and tried to pull him along but Dipper stood his ground. Steven felt himself getting frustrated. "Come on!"

Dipper finally relented. He didn't want Steven to hate him. Steven had that sort of feeling to him- the kind you trusted after only a few minutes of knowing him. That's why he'd brought Steven to the see the orb and structure, and why he automatically trusted his explanation of liking the unknown, despite many unanswered questions. Steven was the kind of person you didn't want to hate you. Not because he was mean or could hurt you, but because he was the kind of person that if you hurt, you would feel really bad about. And Dipper didn't need that kind of guilt.

Steven looked back at him. "You can still ask the yes or no questions as long as we keep moving." He released Dipper's hand.

"Thanks." Dipper smiled. Okay, he just learned that Steven was half alien and he was calm? Wow. This must just be a weird day for him. "Okay, well, did you drop the sphere somewhere?"

Steven pushed aside a few bushes. "No."

"Does it involve magic?"

"Yep."

They approached the shack.

"Should I get the stuff? Your family might be a bit concerned if you come in with a big gash over your eye."

Dipper shook his head. "Nah, it happens a lot. They'll be fine. Besides, they'll see it eventually."

The two boys walked into the shack from the back door and quickly ran up the stairs to the bathroom.

"Okay, I can do this." Steven sat Dipper by the windowsill and quickly found the medical kit. "I don't know much about first aid but I think you clean it off first, right?"

Dipper nodded.

Steven got to cleaning the wound. Aside from many apologies when he was using hydrogen peroxide (he didn't like the fact that it stung) and using a bit too much gauze on Dipper's head (he did it just like Pearl did that one time!) the work was easy enough.

"Steven, we need to stay another day." Pearl gently shook Steven. It was late, about 11:00. "We found what we needed, but we need to stay."

Steven groggily opened his eyes. "Wha' was it?"

"It was an old gem structure, but the gem it housed was missing." Garnet answered. "We need to track it down to stop it from hurting anyone here."

Steven shot awake and sat up. "Was it a platform with a circular gem in the middle?"

"Yes..." Pearl responded cautiously.

"I found that."

The gems looked shocked. "Really?" Amethyst asked.

Steven nodded. "The boy that lives here showed me it. I fought a dragon! And then I bubbled it and sent it back to the temple." His chest swelled with pride.

"Well. I guess we are done here." Pearl looked slightly concerned at the thought of Steven fighting the gem, but he did beat it.

"Good job Steven. We can head back to the temple tonight." Garnet patted Steven's head.

"But wait! Can I go explain stuff because he's really confused and he got hurt and I really need to explain things."

"Who got hurt?" Amethyst questioned, slightly intrigued. "Did the dragon get 'im?"

Steven shook his head. "The boy that showed me it. Dipper. He's right upstairs and I'll be quick. He was chasing me down cause he hunts monsters and he saw me fight the monster. I accidentally hit him."

Pearl looked taken aback. "Steven!"

Steven appeared noticeably upset, one step from tears. "It was an accident!"

Garnet spoke. "It'll be better if we just leave."

"But-"

"Please, Steven." Garnet said.

There was a moment of silence.

"Fine."

Dipper had been alerted of the stranger's presence's several minutes earlier when he came down to get a glass of water. He could hear quiet female voices coming from Steven's room. He leaned up against the door to listen.

"The boy that showed me it. Dipper. He's right upstairs and I'll be quick. He was chasing me down cause he hunts monsters and he saw me fight the monster. I accidentally hit him." Steven's voice drifted through the door. They were talking about him!

He heard another voice, this one light and feminine. "Steven!"

"It was an accident!" It was Steven again, sounding slightly upset.

"It'll be better if we just leave." Another voice, this one deeper (but still female) and near emotionless was heard. How many people were in there?

"But-"

"Please, Steven."

"Fine." He heard footsteps, and he tried to turn down the hall, but the door opened too quickly.

Dipper slowly turned around, hoping they wouldn't notice him. But they did.

There were 3 woman, the tallest at least 7 feet tall. The tall one had a huge square afro and sunglasses (even though it was dark). The next one was even more odd, still tall but shorter with ghostly pale skin. She was extremely skinny, unnaturally so. She had a rock in the middle of her forehead. But she wasn't the weirdest one. There was another woman, who was, surprisingly enough, purple. She wasn't as tall or thin but she was _purple_. Also, she had a half-exposed gemstone in the center of her chest.

This must be the rock aliens Steven was talking about.

But these guys looked so odd, and Steven looked so normal! But there was no time to question that now. The trio had pulled out weapons.

"Who are you?" The purple one asked loudly.

Steven rushed over. "No! This is Dipper! He's nice!"

The women relaxed. "Well why is he here?" The thin one dropped her arm holding a sword.

"I-I heard voices." Dipper stuttered.

Steven looked back and forth between the gems and the boy. Dipper still had the bandages on. He brightened up. "Can I explain now?"

The thin one sighed. "I guess, but make it quick."

"Okay! Dipper, this is Garnet," Steven gestured to the tall one, "Amethyst," the purple one, "And Pearl." The thin one. Garnet and Pearl remained silent while Amethyst feebly waved.

"We are the crystal gems, and we protect humanity and stuff! Mostly from the creatures like you saw today. Or yesterday, I don't know what time it is..."

The next day, Dipper was sitting in his bed, reading the journal.

"Hey, where'd Steven go?" Mabel walked into the room. "He left overnight! And he didn't even say goodbye!"

"It's a long story, but he did what he needed to do." Dipper said.

"Ooh! Was he magic after all!"

Dipper nodded. "I'll tell you later. For now, I need some more sleep."


End file.
